Well, GM is trying to figure out how to trim its massive $5 billion a year healthcare bill. It's going to start by making sure its not paying bills for people it shouldn't be (Reuters):

GM is giving its 67,000 hourly workers until Aug 20 to voluntarily remove ineligible dependents from their health policies, after which, they would have to prove the eligibility of covered-family members through an official document.

If GM learns it is paying for billions in expenses it wasn't supposed to, it may ask employees to reimburse it for the costs (good luck collecting). GM has audited its health-care rolls before, but this effort should be more extensive.